Optical navigation systems detect relative movements between the optical navigation systems and navigation surfaces to perform tracking operations. An optical navigation system uses a light source, such as a light-emitting diode or a laser diode, to illuminate a navigation surface and an image sensor to successively capture optical features of the illuminated navigation surface as frames of image data. These optical features are usually visual surface variations. The optical navigation system compares the successive image frames and estimates the relative movements between the optical navigation system and the navigation surface based on the comparison between the current image frame and a previous image frame. The optical navigation system is able to track the relative movements between the optical navigation system and the navigation surface by continuously capturing and comparing image frames.
Optical navigation systems are commonly used in optical computer mice to track the movements of the mice relative to the surfaces on which the mice are manually manipulated. The tracked movements of an optical computer mouse are used to control a cursor on a computer screen. On a typical navigation surface such as a desktop or a mouse pad, a conventional optical navigation system operates well to track the movements of the mouse across the navigation surface. However, on a clean glass surface, the conventional optical navigation system may not operate accurately or even completely fail to track the movements of the mouse. This is due to the fact that, on a clean glass surface, there may not be sufficient visual surface variations that are detectable by the conventional optical navigation system to properly track the movements of the mouse.
In view of this concern, there is a need for a system and method for performing optical navigation that can operate on different navigation surfaces, including a clean glass surface, in an efficient and effective manner.